"See?" he crowed. "The chair is keyed to mine, somehow; whatever I make mine do, the big one must follow." Hork swung this way and that, laughing like a child with a toy. Dura watched the giant analogue dance clumsily, aping Hork's movements like some huge pet. Presumably, she thought, when the device swiveled, its substance must be moving around her — through her, in fact, like an unreasonable breeze. But she felt nothing — at least, no more than an inner chill which could as easily be caused by her awe and fear.

At last Hork tired of his games. "I can make it do whatever I want." He looked a little more thoughtful. "And so if I pull these levers..."

"No. We need to work this out, Hork." She looked up. "This — ghost, this City-sized artifact — is a seat big enough for a giant..."

"That's obvious. But..."

"But," she interrupted, "a giant of a certain form... a human-shaped giant, meters tall." She studied his face, waiting for him to reach the same conclusions.

"Meters... The Ur-humans."

She nodded. "Hork, I think the ghost-seat is an Ur-human device. I think we're in a little bubble of Air, floating inside an Ur-human room."

She tilted her head back on her neck, feeling the flesh at the top of her spine bunch under her skull, and looked up into a ghost-room which abruptly made sense.

They were inside a huge Ur-human chair. But there were other chairs — four of them, she counted, receding into mistiness, like a row of cities. The chairs were placed before a long, flat surface, and she caught hints of a complex structure beneath and behind that surface. Perhaps that was some form of control panel. Looking further out, the tetrahedral structure surrounding all of this was a sketch drawn against fog.

Hork touched her arm. "Look over there." He pointed. On the side of the Ur-human room opposite the row of seats there was a bank of billowing gas — but that must be wrong, of course; she tried to forget her smallness, to see this through Ur-human eyes. It was a structure made up of something soft, pliable, piled up on a lower flat surface. It looked like a cocoon, laid flat.

Did the Ur-humans sleep?

Again Hork was pointing. "On top of that surface before the chairs. See? Instruments, built for giant hands."

Dura saw a cylinder longer than a Crust-tree trunk. Its end was sharp, protruding over the lip of the surface. Perhaps it was a stylus, as she'd seen Deni Maxx use in the Hospital. She tried to imagine the hand that could grasp a tree trunk and use it to write notes... Beside the "stylus" there was another cylinder, but this was set upright. It seemed to be hollow — the cylinder was transparent to Dura's eyes, and she could make out a structure of thick walls surrounding an empty space — and there was no upper surface.